1. Field of the Invention
The present invention relates generally to medical devices and methods. More particularly, the present invention provides luminal prostheses, such as vascular stents and grafts for reducing or inhibiting restenosis.
The present invention relates generally to medical devices and methods. More particularly, the present invention provides luminal prostheses, such as vascular stents and grafts for reducing or inhibiting restenosis.
A number of percutaneous intravascular procedures have been developed for treating stenotic atherosclerotic regions of a patient's vasculature to restore adequate blood flow. The most successful of these treatments is percutaneous transluminal angioplasty (PTA). In PTA, a catheter, having an expandable distal end usually in the form of an inflatable balloon, is positioned in the blood vessel at the stenotic site. The expandable end is expanded to dilate the vessel to restore adequate blood flow beyond the diseased region. Other procedures for opening stenotic regions include directional arthrectomy, rotational arthrectomy, laser angioplasty, stenting, and the like. While these procedures have gained wide acceptance (either alone or in combination, particularly PTA in combination with stenting), they continue to suffer from significant disadvantages. A particularly common disadvantage with PTA and other known procedures for opening stenotic regions is the frequent occurrence of restenosis.
Restenosis refers to the re-narrowing of an artery after an initially successful angioplasty. Restenosis afflicts approximately up to 50% of all angioplasty patients and is the result of injury to the blood vessel wall during the lumen opening angioplasty procedure. In some patients, the injury initiates a repair response that is characterized by smooth muscle cell proliferation referred to as “hyperplasia” in the region traumatized by the angioplasty. This proliferation of smooth muscle cells re-narrows the lumen that was opened by the angioplasty within a few weeks to a few months, thereby necessitating a repeat PTA or other procedure to alleviate the restenosis.
A number of strategies have been proposed to treat hyperplasia and reduce restenosis. Previously proposed strategies include prolonged balloon inflation during angioplasty, treatment of the blood vessel with a heated balloon, treatment of the blood vessel with radiation following angioplasty, stenting of the region, and other procedures. While these proposals have enjoyed varying levels of success, no one of these procedures is proven to be entirely successful in substantially or completely avoiding all occurrences of restenosis and hyperplasia.
As an alternative or adjunctive to the above mentioned therapies, the administration of therapeutic agents following PTA for the inhibition of restenosis has also been proposed. Therapeutic treatments usually entail pushing or releasing a therapeutic capable agent through a catheter or from a stent. While holding great promise, the delivery of therapeutic agents for the inhibition of restenosis has not been entirely successful.
As an alternative or adjunctive to the above mentioned therapies, the administration of therapeutic agents following PTA for the inhibition of restenosis has also been proposed. Therapeutic treatments usually entail pushing or releasing a drug through a catheter or from a stent. While holding great promise, the delivery of therapeutic agents for the inhibition of restenosis has not been entirely successful.
Accordingly, it would be a significant advance to provide improved devices and methods for reducing, inhibiting, or treating restenosis and hyperplasia which may follow angioplasty and other interventional treatments. This invention satisfies at least some of these and other needs.
2. Description of the Background Art
Local drug delivery for the prevention of restenosis is described in Lincoff et al. (1994) Circulation 90:2070-2084. A full description of an exemplary luminal prosthesis for use in the present invention is described in co-pending application Ser. No. 09/565,560 filed May 4, 2000, the full disclosure of which is incorporated herein by reference. Method and apparatus for releasing active substances from implantable and other devices are described in U.S. Pat. Nos. 6,096,070; 5,824,049; 5,624,411; 5,609,629; 5,569,463; 5,447,724; and 5,464,650. The use of stents for drug delivery within the vasculature are described in PCT Publication No. WO 01/01957 and U.S. Pat. Nos. 6,099,561; 6,071,305; 6,063,101; 5,997,468; 5,980,551; 5,980,566; 5,972,027; 5,968,092; 5,951,586; 5,893,840; 5,891,108; 5,851,231; 5,843,172; 5,837,008; 5,769,883; 5,735,811; 5,700,286; 5,679,400; 5,649,977; 5,637,113; 5,591,227; 5,551,954; 5,545,208; 5,500,013; 5,464,450; 5,419,760; 5,411,550; 5,342,348; 5,286,254; and 5,163,952. Biodegradable materials are described in U.S. Pat. Nos. 6,051,276; 5,879,808; 5,876,452; 5,656,297; 5,543,158; 5,484,584; 5,176,907; 4,894,231; 4,897,268; 4,883,666; 4,832,686; and 3,976,071. The use of hydrocylosiloxane as a rate limiting barrier is described in U.S. Pat. No. 5,463,010. Methods for coating of stents is described in U.S. Pat. No. 5,356,433. Coatings to enhance biocompatibility of implantable devices are described in U.S. Pat. Nos. 5,463,010; 5,112,457; and 5,067,491. Porous and non-porous materials for drug delivery, coating, and other uses are described in U.S. Pat. Nos. 5,488,015; 5,470,802; 5,428,123; 5,288,504; 5,270,047; 5,243,756; 5,130,889; 4,788,063; 3,993,072; and 3,854,480. Energy-based devices are described in U.S. Pat. Nos. 6,031,375; 5,928,145; 5,735,811; 5,728,062; 5,725,494; 5,409,000, 5,368,557; 5,000,185; and 4,936,281. Magnetic processes, some of which have been used in drug delivery systems, are described in U.S. Pat. Nos. 5,427,767; 5,225,282; 5,206,159; 5,069,216; 4,904,479; 4,871,716; 4,501,726; 4,357,259; 4,345,588; and 4,335,094.
The disclosure of this application is related to the disclosures of the following applications: Ser. No. 09/782,927, now U.S. Pat. No. 6,471,980; Ser. No. 09/783,254; and Ser. No. 09/782,804.
The full disclosures of each of the above references are incorporated herein by reference.